Fusion is the process by which all the stars in the universe shine. All of the energy on Earth comes ultimately from fusion processes going on inside the sun. It's incredibly difficult to achieve because forces and pressures and temperatures you need to push atoms together are astonishing. NIF has now been able to make fusion happen, but they also got more out of it than they did before. They hope that imploding a small pellet of fuel will help them do this.
Scientists have reported a long-awaited nuclear-fusion breakthrough, using lasers to ignite hydrogen-isotope fuel in a self-sustaining burn. But that marks just one step on a long, uncertain road to clean fusion energy. Same-sex marriage in America is now protected by legislation, in a compromise that could provide a template for future culture-war clashes. And the uncertain future of Darjeeling teas.
Help us make the show better: take our listener survey at http://economist.com/intelligencesurvey
For full access to print, digital and audio editions of The Economist, subscribe here www.economist.com/intelligenceoffer